Disconnect relays used in meters today are expensive due to high part count, complexity, copper content, and precious metals content. Further, disconnect relays in the market place today typically use methods such as flexible conductor “arms”/contact “arms” that have practical limitations that necessitate lower contact force (i.e. in 2-3.5 Newtons (N) range). Contacts commonly used in meter service disconnect relays today typically use a silver tin alloy. The silver tin contacts under a fault condition will flow (or sacrifice) the silver to the outer edge of the contact surface. Depending on the severity and frequency of surge/s the copper substrate will be exposed and the contact silver will have an irregular surface. These conditions create higher resistance and arching that hastens the disconnect relay failure through either high heat rise and plastics melting or loss of relay connection. Further, common disconnect relays in the field today often weld after one to two 7000 amp fault conditions for 6 electrical cycles and may not operate or have a significantly shortened contact life. Further, systems commonly used today typically will not survive 12000 amp fault conditions for 4 electrical cycles. In contrast, the market available relays used in today's meters generally have contact blow-off and often break their housing/insulation in the 12000 KVA 4 electrical cycle test.
Therefore, disconnect relays and contact materials that overcome challenges in the art, some of which are described above, are desired.